[PATCH v2] x86-64: don't allow use of %axl as accumulator

[Jan Beulich]

>>> On 14.11.17 at 13:37, <hjl.tools@gmail.com> wrote:
> On Tue, Nov 14, 2017 at 12:17 AM, Jan Beulich <JBeulich@suse.com> wrote:
>> --- 2017-11-10/gas/testsuite/gas/i386/x86-64-reg-bad.s
>> +++ 2017-11-10/gas/testsuite/gas/i386/x86-64-reg-bad.s
>> @@ -0,0 +1,18 @@
>> +# Check %axl / %cxl aren't permitted as accumulator / shift count, but
>> +# make sure any of the extended low registers still work as intended
>> +       .text
>> +reg:
>> +       movabs  -1, %axl
>> +       add     $1, %axl
>> +       add     $1, %cxl
>> +       add     $1, %dxl
>> +       add     $1, %bxl
>> +       add     $1, %spl
>> +       add     $1, %bpl
>> +       add     $1, %sil
>> +       add     $1, %dil
> 
> Please move
> 
> +       add     $1, %axl
> +       add     $1, %cxl
> +       add     $1, %dxl
> +       add     $1, %bxl
> +       add     $1, %spl
> +       add     $1, %bpl
> +       add     $1, %sil
> +       add     $1, %dil
> 
> to x86-64-specific-reg.s.   OK with that change.

How would that work? That test is run without "-al", hence the
test wouldn't actually verify that an empty REX prefix is being
generated (which aiui is the main purpose of the test). Please
clarify whether you mean me to add "-al".

Jan